Method of using a gas-phase reactor system including analyzing exhausted gas

ABSTRACT

Methods of and systems for performing leak checks of gas-phase reactor systems are disclosed. Exemplary systems include a first exhaust system coupled to a reaction chamber via a first exhaust line, a bypass line coupled to a gas supply unit and to the first exhaust system, a gas detector coupled to the bypass line via a connecting line, a connecting line valve coupled to the connecting line, and a second exhaust system coupled to the connecting line. Methods include using the second exhaust system to exhaust the connecting line to thereby remove residual gas in the connecting line that may otherwise affect the accuracy of the gas detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/858,224 filed on Jun. 6, 2019, the disclosure ofwhich is incorporated herein in its entirety by reference.

FIELD OF INVENTION

The present disclosure generally relates to gas-phase methods andsystems. More particularly, the disclosure relates to gas-phase systemsthat include leak detection apparatus and to methods of detecting leakswithin the system.

BACKGROUND OF THE DISCLOSURE

Gas-phase reactors, such as chemical vapor deposition (CVD),plasma-enhanced CVD (PECVD), atomic layer deposition (ALD), and the likecan be used for a variety of applications, including cleaning,depositing and etching materials on a substrate surface. For example,gas-phase reactors can be used to clean, deposit and/or etch layers on asubstrate to form semiconductor devices, flat panel display devices,photovoltaic devices, microelectromechanical systems (MEMS), and thelike.

A typical gas-phase reactor system includes a reactor including areaction chamber, one or more precursor and/or reactant gas sourcesfluidly coupled to the reaction chamber, one or more carrier and/orpurge gas sources fluidly coupled to the reaction chamber, a gasdistribution system to deliver gases (e.g., precursor and/or reactantgas(es) and/or carrier or purge gas(es)) to a surface of a substrate,and an exhaust source fluidly coupled to the reaction chamber.

Many gas-phase reactors include a gas supply unit to supply desiredgases to the reaction chamber. A gas supply unit can include one or moresources (or connections to sources), which may be solid, liquid, or gas,at standard room temperature and pressure, valves, including shutoffand/or control valves, lines, heaters, coolers, and the like. The gassupply unit can also include a housing that surrounds the one or moresources, lines, valves, heaters, and/or coolers.

For various reasons, including safety, it may be desirable to detect gasleakage within the gas supply unit. For example, during operation of agas-phase reactor system, a valve failure or failure of a gas supplyblock, for example, may lead to leakage of gas, which, in turn, can makeit difficult to control the gas flow rate, and can lead to processand/or reactor system failure. Accordingly, it is generally desirable todetect gas leakage within a gas supply unit as soon as possible.

FIG. 1 illustrates a gas-phase reactor system 100 that includes a gassupply unit 102, a reactor 104, an exhaust system 106, a gas detector108, and a controller 110. System 100 also includes a gas inlet 112,valves 114-122, and an exhaust path 124.

In the illustrated example, gas supply unit 102 and reactor 104 areconnected via gas inlet 112. Process gas is supplied to reactor 104through a gas inlet valve 114 and gas inlet 112. Gas inlet valve 114 canbe a part of gas supply unit 102 and gas inlet 112 can include a gassupply apparatus, such as a showerhead or the like. Gas from reactor 104is exhausted to exhaust system 106 via exhaust path 124. Exhaust system106 can include, for example, a dry pump, a scrubber or the like.Exhaust path 124 can include exhaust valve 116. Exhaust valve 116 canfunction to control a pressure in the reactor 104 by being equipped witha pressure control device, e.g., a butterfly wing plate, and it may becontrolled by an exhaust valve control unit (not shown) thatcommunicates with a pressure gauge (not shown) installed at reactor 104.

System 100 also includes a divert or bypass path 126. Divert path 126 isconnected to gas supply unit 102 and exhaust path 124, and bypasses gasinlet 112, reactor 104 and valve 116. Divert path 126 is especiallyuseful in ALD-type processes to facilitate keeping a process pressure inreactor 104 constant during a process, because divert path 126 can beused to switch a gas flow direction to divert path 126 from reactor 104by adjusting valve movements, without increasing or decreasing the gasflow rate. By keeping the process pressure constant, pressurefluctuation in the gas supply line and reactor 104 may be minimized andthe process may be more stable.

In the illustrated example, divert path 126 includes a first divertvalve 120, a second divert valve 122 and a third divert valve 118. Whengas is supplied to reactor 104, first divert valve 120 and a thirddivert valve 118 are closed. When gas is supplied to divert path 126,first divert valve 120 and third divert valve 122 are open.

Gas detector 108 is fluidly coupled to divert path 126 to check for gasleakage within gas supply unit 102. For example, when a valve or a partof an integrated gas supply system block of the gas supply unit failsand outer gas leaks into the gas supply unit 102 through a failedportion of the integrated gas supply system block, gas detector 108 maydetect the leaking gas and send a signal to controller 110, andcontroller 110 can cause stoppage of the operation of a portion of thesystem 100 (dotted line area of FIG. 1).

FIG. 2 illustrates a leak check method 200 of a gas-phase reactorsystem, such as gas-phase reactor system 100. Method 200 includes thesteps of loading a substrate within a reactor (step 202), leak checkingthe gas supply unit (step 204), determining whether a leak rate isgreater than a predetermined value (step 206), start substrateprocessing (step 208), stop system operation (step 210), and end processand unload substrate (step 212).

During step 202, a substrate is loaded to the reactor (e.g., reactor104). The substrate may be mounted on, for example, a susceptor or aheating block.

During steps 204 and 206, a leak check of the gas supply unit 102 iscarried out. During step 204, all valves of the gas supply unit 102 areopen, and the gas inlet valve 114 and foremost valves (not illustrated)of gas supply unit 102, through which gases, such as precursors,reactants and other process gases flow into gas supply unit 102 from agas reservoir or vessel (not shown) are closed. Instead, first divertvalve 120, second divert valve 122 and third divert valve 118 are open.In this case, all portions of gas supply unit 102 are in fluidcommunication with divert path 126 and gas detector 108, without beingin open fluid communication with gas inlet 112 and reactor 104 and gasreservoirs or vessels external to gas supply unit 102. During step 204,gas detector 108 detects any residual gas exhausted from gas supply unit102, flowing to divert path 126. During step 206, if the residual gascontains outer gas, such as N₂ or O₂, originated from the atmosphere,and as a result, the leak rate of the gas is over the set value, gasdetector 108 can send a signal to controller 110. If a leak is detected,controller 110 can be configured to cause stoppage of the operationsystem 100 (step 210). Steps 204 and 206 can be performed during apreprocess step of the substrate, such as a preheating step.

Based on the detection results during step 206, a process may beperformed (step 208). The process may be or include film deposition,etching, ashing, cleaning, or the like. If the detection results exceedthe set value, the substrate processing system may stop the operation(step 210). In other embodiments, the detection results may besynchronized with an interlock system.

In this case, if the detection result is over the set value, theinterlock system stops the operation.

At step 212, when the process is completed, a substrate is unloaded fromthe reactor and the next substrate is loaded and steps 202-212 arerepeated. In other words, the leak detection of the gas supply unit 102is performed repeatedly after a substrate is loaded within a reactionchamber and before processing the substrate from the reaction chamber.

Leak detection of gas supply unit 102 using system 100 and method 200may exhibit low accuracy in detecting outer gas due to trapped gas in anarea 128. Area 128 may be a gas pipe connecting divert path 126 and gasdetector 108. Area 128 desirably includes minimal residual gas ortrapped gas in it for accurate leak detection of gas supply unit 102after completing step 204 and step 206. But, due to the subsequentsubstrate processing step 208 right after the leak detecting steps 204and 206, second divert valve 122 is closed to protect gas detector 108from process gas flowing into divert path 126, thereby trapping gas inthe area 128. The trapped gas in area 128 may obstruct the accurate andprecise leak detection during step 204 and step 206 before processingthe next substrate. In another case, gas from the gas supply unit may beaccumulated in area 128 during steps 204 and 206, and the accumulatedgas may make it difficult to detect the outer gas accurately.Accordingly, improved systems and methods for detecting leaks ingas-phase reactor systems are desired.

Any discussion of problems and solutions set forth in this section hasbeen included in this disclosure solely for the purposes of providing acontext for the present disclosure, and should not be taken as anadmission that any or all of the discussion was known at the time theinvention was made.

SUMMARY OF THE DISCLOSURE

Various embodiments of the present disclosure relate to gas-phasereactor systems and methods. While the ways in which various embodimentsof the present disclosure address drawbacks of prior methods and systemsare discussed in more detail below, in general, exemplary embodiments ofthe disclosure provide improved systems and methods for detecting gasleaks within a gas-phase reactor system.

In accordance with at least one embodiment of the disclosure, agas-phase reactor system includes a reactor comprising a reactionchamber; a gas supply unit coupled to the reaction chamber via a gassupply line; a first exhaust system coupled to the reaction chamber viaa first exhaust line; a bypass line coupled to the gas supply unit andto the first exhaust system; a gas detector coupled to the bypass linevia a connecting line; a connecting line valve coupled to the connectingline; and a second exhaust system coupled to the connecting line. Inaccordance with exemplary aspects of these embodiments, the bypass lineis coupled to the gas supply line. The bypass line can also be coupledto the first exhaust line. In accordance with further aspects, thegas-phase reactor system includes a second exhaust line coupled to theconnecting line. A second exhaust line valve can be between theconnecting line and the second exhaust system. Further, the secondexhaust system can be coupled to a chamber, such as a platform chamberor an outer chamber. The gas detector can detect a flowrate and/or acomposition (e.g., nitrogen and/or oxygen content) of a gas. Thegas-phase reactor system can also include a controller configured to:cause the gas-phase reactor system to perform a leak test after asubstrate has been loaded into the reaction chamber and before thesubstrate is removed from the reaction chamber, cause the gas-phasereactor system to perform a leak test while heating a substrate to adesired process temperature, perform a leak test during a process cycle,stop flow of gas to the reaction chamber when the gas detector detects aflow rate of gas above a predetermined value, stop operation of thegas-phase reactor system when the gas detector detects a flow rate ofgas above a predetermined value, exhaust the connecting line during asubstrate process within the reaction chamber, and/or exhaust theconnecting line by closing the connecting line valve and opening thesecond exhaust line valve.

In accordance with at least one other embodiment of the disclosure, amethod of using a gas-phase reactor system includes the steps ofproviding a gas-phase reactor system, such as providing a gas-phasereactor system described herein, exhausting the connecting line, and,using the gas detector, analyzing gas exhausted from the gas-phasereactor system. The gas can be exhausted from the gas supply unit. Themethod can further include a step of closing a second exhaust line valvebetween the gas detector and the second exhaust system after the step ofexhausting the connecting line and prior to the step of analyzing gas.Additionally or alternatively, the method can include a step ofexhausting the bypass line during the step of analyzing. Exemplarymethods can include a step of loading a substrate within the reactionchamber, wherein the step of analyzing is performed after the step ofloading and before a step of unloading the substrate from within thereaction chamber. Alternatively, the method can include a step ofloading a substrate within the reaction chamber, wherein the step ofanalyzing is performed before the step of loading. During the step ofanalyzing, gas can be exhausted to the second exhaust system. The gasdetector can be used to detect a composition and/or flowrate of a gas.For example, the gas detector can be used to determine whether a gasflow rate is above a predetermined level. In this case, the method caninclude if the gas flow rate is above the predetermined level, stoppingflow of gas to the reaction chamber, if the gas flow rate is above thepredetermined level, stopping operation of the gas-phase reactor system,and/or if the gas flow rate is above the predetermined level, engagingan interlock system. The step of analyzing can be performed whileheating a substrate to a desired process temperature, during a processcycle, and/or after a substrate has been loaded into the reactionchamber and before the substrate is removed from the reaction chamber.

These and other embodiments will become readily apparent to thoseskilled in the art from the following detailed description of certainembodiments having reference to the attached figures; the invention notbeing limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of exemplary embodiments of the presentdisclosure can be derived by referring to the detailed description andclaims when considered in connection with the following illustrativefigures.

FIG. 1 illustrates a gas-phase reactor system of the prior art.

FIG. 2 illustrates a leak detection method of the prior art.

FIGS. 3-7 and 10 illustrate a gas-phase reactor system in accordancewith at least one embodiment of the disclosure.

FIG. 8 illustrates leak check results using a system known in the art.

FIG. 9 illustrates leak check results using a system or method inaccordance with at least one embodiment of the disclosure.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help improve understanding ofillustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below.

The present disclosure generally relates to gas-phase reactor systemsand methods capable of determining a leak. As set forth in more detailbelow, exemplary systems and methods described herein can be used tomore accurately determine a composition, flow rate, and/or amount of gasleaking from one or more areas or sections of a gas-phase reactorsystem. Further, the systems and methods described herein may be moreefficient in processing substrates and performing leak checks, comparedto traditional methods and systems.

In this disclosure, “gas” can include material that is a gas at roomtemperature and pressure, a vaporized solid and/or a vaporized liquid,and may be constituted by a single gas or a mixture of gases, dependingon the context. A gas other than the process gas, i.e., a gas introducedwithout passing through a gas distribution assembly, such as ashowerhead, other gas distribution device, or the like, may be used for,e.g., sealing the reaction space, which includes a seal gas, such as arare gas. A gas can be a reactant or precursor that takes part in areaction within a reaction chamber and/or include ambient gas, such asair.

In this disclosure, “line” can refer to a conduit, such as a tube,through which gas flows. A line can include one or more valves,branches, or the like. Exemplary lines as described herein can be formedof stainless steel.

In this disclosure, any two numbers of a variable can constitute aworkable range of the variable as the workable range can be determinedbased on routine work, and any ranges indicated may include or excludethe endpoints. Additionally, any values of variables indicated(regardless of whether they are indicated with “about” or not) may referto precise values or approximate values and include equivalents, and mayrefer to average, median, representative, majority, etc. in someembodiments. Further, in this disclosure, the terms “constituted by” and“having” refer independently to “typically or broadly comprising,”“comprising,” “consisting essentially of,” or “consisting of” in someembodiments. In this disclosure, any defined meanings do not necessarilyexclude ordinary and customary meanings in some embodiments.

In this disclosure, “continuously” can refer to one or more of withoutbreaking a vacuum, without interruption as a timeline, without anymaterial intervening step, without changing treatment conditions,immediately thereafter, as a next step, or without an interveningdiscrete physical or chemical structure between two structures otherthan the two structures in some embodiments.

Turning again to the figures, FIG. 3 illustrates a gas-phase reactorsystem 300 in accordance with exemplary embodiments of the disclosure.Gas-phase reactor system 300 includes a reactor 302 comprising areaction chamber 304, a gas supply unit 306, a first exhaust system 308,a bypass line 310 coupled to gas supply unit 306 and to the firstexhaust system 308, a gas detector 312, and a second exhaust system 314.Gas-phase reactor system 300 can also include a controller 316 tocontrol various portions or devices of gas-phase reactor system 300.

Reactor 302 can include any suitable gas-phase reactor. By way ofexamples, reactor 302 can be configured as a chemical vapor depositionreactor, an atomic layer deposition reactor, an etch reactor, a cleanreactor, an epitaxial reactor, or the like. In some cases, reactor 302can include a direct plasma configuration and/or gas-phase reactorsystem 300 can include a remote plasma unit coupled to reactor 302.Reactor 302 includes a gas inlet 318 to receive gas from gas supply unit306.

Gas supply unit 306 supplies one or more process gases, such as one ormore precursors and/or one or more reactants to reaction chamber 304through gas inlet 318. Gas supply unit 306 can also provide a carrierand/or inert gas to the reaction chamber through gas inlet 318. Gassupply unit 306 can include an integrated gas supply block. Theintegrated gas block system is a block-typed or Lego-typed gas supplysystem, so as to make the whole gas supply path from the foremost valveto the hindmost valve simple, compact and short, and reduce the blindspots between gas supply path and a valve, compared to conventionalplumbing-typed gas supply systems. So the gas supply or switchingbetween gases may be faster in the integrated gas block system than inthe conventional plumbing system.

First exhaust system 308 and second exhaust system 314 can include anysuitable device to exhaust a line and/or reaction chamber. By way ofexamples, first exhaust system 308 and/or second exhaust system 314 canbe or include a dry pump, a scrubber, a turbomolecular pump, or thelike. As illustrated in FIG. 3, second exhaust system 314 can be coupledto another chamber 320, such as a platform chamber for transferringsubstrates between a reactor and a cooler or load-lock, or an outerchamber with a rotation arm encompassing multiple reactors in amulti-reactor chamber.

A line 338 can connect reactor 302 to first exhaust system 308. Asillustrated, line 338 can include a valve 340, which can be coupled toand controlled by controller 316.

Bypass line 310 is coupled to gas supply unit 306 and to first exhaustsystem 308. Bypass line 310 includes a first bypass line valve 322between gas supply unit 306 and first exhaust system 308. Bypass line310 can additionally or alternatively include a second bypass line valve324. First and second bypass line valves 322 and 324 can include anysuitable type valve, such as a pneumatic valve. First and second bypassline valves 322 and/or 324 can be coupled to and controlled bycontroller 316.

Gas detector 312 can detect or measure a flowrate and/or composition ofa gas. By way of examples, gas detector 312 can be or include, forexample, SPOES (Self-Plasma Optical Emission Spectroscopy) whichdecomposes gas, analyzes and detects a type of gas. For example, sincenitrogen takes up about 70% of the atmosphere, gas detector 312 may beconfigured to detect nitrogen in a gas. In some cases, if the nitrogenis detected by gas detector 312, and the detected nitrogen is over theset value, it may be determined that an outer gas (e.g., from anenvironment surrounding gas supply unit 306) has leaked into gas supplyunit 306 and/or elsewhere within gas-phase reactor system 300.Additionally or alternatively, gas detector 312 can include a flow meterand/or a mass flow meter to determine an amount or a flowrate of a leak.

A connecting line 330 can connect bypass line 310 to gas detector 312.Connecting line 330 can include a connecting line valve 332, which canbe a pneumatic valve and which can be coupled to controller 316.

Controller 316 can be any suitable controller that can cause varioussteps or functions as described herein to be performed. In accordancewith various examples of the disclosure, controller 316 receives signalsfrom gas detector 312 that can indicate a composition, flowrate, and/oramount of gas. As discussed in more detail below, controller 316 can beconfigured to cause one or more of: cause the gas-phase reactor systemto perform a leak test after a substrate has been loaded into thereaction chamber and before the substrate is removed from the reactionchamber, cause the gas-phase reactor system to perform a leak test whileheating a substrate to a desired process temperature, perform a leaktest during a process cycle, stop flow of gas to the reaction chamberwhen the gas detector detects a flow rate of gas above a predeterminedvalue, stop operation of the gas-phase reactor system when the gasdetector detects a flow rate of gas above a predetermined value, exhaustthe connecting line during a substrate process within the reactionchamber, and exhaust the connecting line by closing connecting linevalve 332 and opening a second exhaust line valve 336 based on one ormore signals received from gas detector 312.

Gas supply unit 306 and reactor 302 are connected via gas inlet 318.Process gas can be supplied to reactor 302 through a gas inlet valve 326in a gas inlet line 328. Although separately illustrated, gas inletvalve 326 can be a part of gas supply unit 306. Gas inlet 318 caninclude a gas supply apparatus, such as showerhead or the like.

As illustrated, gas-phase reactor system 300 can include a secondexhaust line 334 coupled to connecting line 330. Second exhaust line 334can also be coupled to second exhaust system 314. Second exhaust line334 can include second exhaust line valve 336, which can be a pneumaticvalve or the same or similar to a check valve through which gas flowsforward, not flowing back, and which can be coupled to and controlled bycontroller 316.

As set forth in more detail below, use of gas-phase reactor system 300has several advantages over use of conventional gas-phase reactorsystems. For example, while processing a substrate using gas-phasereactor system 300, during a substrate processing (e.g., deposition,etch, or clean step), connecting line valve 332 can be closed (e.g.,using controller 316) and second exhaust line valve 336 can be open(e.g., opened using controller 316), such that residual gas trapped oraccumulated gas in an area (i.e., blind spot) 342 may be exhausted tosecond exhaust system 314 through second exhaust line 334. In otherwords, by adopting this system, any gas that would otherwise be trappedin connecting line 330 can be mitigated, thereby improving the accuracyof measurements performed using gas detector 312. Further, process gascan include compounds that are generated by the reaction between processgases in areas between reaction chamber 304 and first exhaust system308; these compounds can be deposited and stuck in first exhaust system308. This may make switching between exhaust of gas in bypass line 310,coupled to gas supply unit 306 and to first exhaust system 308, and line338 coupled between reaction chamber 304 and first exhaust system 308,to first exhaust system 308 not be smooth. However, using system 300,second exhaust line 334 and the second exhaust system 314 can be usedmitigate abrupt transition to first exhaust system 308 and therebyprovide for more accurate analysis and detection of, for example, outergas leaked into the gas supply unit 306 and other gas leaks withingas-phase reactor system 300. Further, outgassing effect from thechemical compounds deposited on the inside wall of line 338 can obstructthe smooth exhaust from bypass line 310. This effect is especiallysevere in processes that generate a lot of by-products such as powder,for example, SiN process using DCS(dichlorosilane) and NH₃ as processgas, and lower the accuracy of the analysis of leaked gas into the gassupply unit 306 because of the residual gas in the bypass line 310. Soit's necessary to remove residual gas in the bypass line 310 foraccurate analysis of leaked gas into the gas supply unit 306.

FIGS. 4-7 and 10 illustrate gas-phase reactor system 300 duringprocessing in accordance with additional embodiments of the disclosure.FIGS. 4 and 5 illustrate gas-phase reactor system 300 while performing aleak check after loading a substrate within a reaction chamber (e.g.,reaction chamber 304) and prior to processing the substrate (e.g., priorto introducing reaction gases into reaction chamber 304). FIGS. 6 and 7illustrate another example of gas-phase reactor system 300 whileperforming a leak check step after loading a substrate and beforeprocessing the substrate. And, FIG. 10 illustrates yet another exampleof gas-phase reactor system 300 while performing a leak check step.

As illustrated in FIG. 4, after a substrate is loaded within reactionchamber 304, first bypass line valve 322, second bypass line valve 324and second exhaust line valve 336 are initially open or can be openedusing controller 316. Gas inlet valve 326 is initially closed or can beclosed using controller 316. Connecting line valve 332 is closed forcertain period of time, e.g., less than 10 seconds, e.g., usingcontroller 316, so as to remove any potential residual gas area 342between a connecting line valve 332 and a gas detector 312.

Next, as illustrated in FIG. 5, first bypass line valve 322, connectingline valve 332 and second bypass line valve 324 are open (e.g., byopening using controller 316). Gas inlet valve 326 is closed (e.g.,using controller 316). Second exhaust line valve 336 is closed forcertain period of time, e.g., less than 5 seconds—e.g., using controller316. Next, gas detector 312 starts detecting and analyzing gas exhaustedfrom the gas supply unit 306 and/or elsewhere in gas-phase reactorsystem 300.

As illustrated in FIG. 6, in accordance with another embodiment of thedisclosure, after a substrate is loaded within reaction chamber 304,first bypass line valve 322, second bypass line valve 324 and secondexhaust line valve 336 are open or can be opened using, for example,controller 316. Gas inlet valve 326 is closed or can be closed using,for example, controller 316. Connecting line valve 332 is closed forcertain period of time, e.g., less than 10 or 5 seconds, using, e.g.,controller 316, so as to remove any potential residual gas from the area342 between connecting line valve 332 and gas detector 312.

Next, as illustrated in FIG. 7, first bypass line valve 322, connectingline valve 332 and second exhaust line valve 336 are open or areopened—e.g., using controller 316. Gas inlet valve 326 is closed—e.g.,using controller 316. Second bypass line valve 324 is closed, e.g.,using controller 316, for certain period of time, e.g., less than 10 or5 seconds. Gas detector 312 then starts detecting and analyzing gasexhausted from the gas supply unit 306. In this embodiment, gasexhausted from gas supply unit 306 is exhausted to second exhaust system314, so that any blocking effect from first exhaust system 308 and/or afirst exhaust path (e.g., line 338) can be avoided. This procedure maybe particularly useful in processes capable of producing a lot ofbyproducts, such as powder, e.g., silicon nitride deposition processesthat use DCS and NH₃ as process gases.

In accordance with illustrative examples, during processing of asubstrate, connecting line valve 332 is closed and second exhaust linevalve 336 is opened (e.g., using controller 316) to prevent or mitigateany residual gas from being detected during processing a substrate.

FIG. 10 illustrates another example, in which bypass line valve 322,connecting line valve 332, second bypass line valve 324, and secondexhaust line valve 336 are open in a leak check step. In this case, gascan be evacuated from line 342 as described above by closing connectingline valve 332 certain period of time, e.g., less than 10 or 5 seconds,using, e.g., controller 316, so as to remove any potential residual gasfrom the area 342 between connecting line valve 332 and gas detector312. Then, bypass line valve 322, connecting line valve 332, secondbypass line valve 324 and second exhaust line valve 336 are open or canbe opened—e.g., using controller 316—during a leak check, such that gasis exhausted to both first exhaust system 308 and second exhaust system314 during the leak check. Valve 340 can be open during this step. Thisexample can be performed before or after processing a substrate.

FIG. 8 illustrates leak check results using the gas-phase reactor systemillustrated in FIG. 1. FIG. 8 illustrates consolidated graphs, showingnitrogen intensity per each leak rate test of gas supply unit 102 whenmultiple substrates (four in the illustrative example) were processedsuccessively. In FIG. 8, the Y-axis is the intensity of nitrogendetected by a gas detector (e.g., gas detector 108) at each leak ratetest. The X-axis is a substrate process time which includes a leakdetecting step. It took about 150 seconds for each substrate to beprocessed.

As illustrated in FIG. 8, the more the leak rate increases, the greaterthe nitrogen intensity. But, the nitrogen intensity is not uniform andgradually increases as multiple substrates are successively processed.In addition, the nitrogen intensity is detected during the entiresubstrate processing time, and a leak detecting step is not distinctfrom a substrate processing step. This is because the gas detector(e.g., gas detector 108) keeps detecting the residual gas in the blindspot area 128 in FIG. 1 during substrate processing step—even thoughvalve 122 is closed. The trapped residual gas can accumulate in theblind spot area and can affect the detection results of the followingsubstrate. For example, some of the nitrogen intensity of the secondsubstrate may come from that of residual gas trapped in the blind spotarea during substrate processing of the first substrate. So the leakdetection and analysis of the gas supply unit is not accurate and isunreliable.

In contrast, FIG. 9 illustrates the leak check results using gas-phasereactor system 300 in accordance with examples of the disclosure.Contrary to the results illustrated in FIG. 8, FIG. 9 illustrates a leakdetecting step is clearly distinct from a substrate processing step. Anitrogen intensity is uniform regardless of the number of processedsubstrates. This is thought to be because residual gas in the blind spotarea 342 is exhausted to the second exhaust system 314 through a seconddivert path before the leak detecting step begins.

Therefore, according to examples of the disclosure, a set (e.g.,intensity, flowrate, or the like) value may be made. If a measured value(e.g., intensity, flowrate, or the like) is over the set value, aninterlock system may be used to stop the operation of system 300. Asmentioned above, during processing a substrate at the substrateprocessing step, connecting line valve 332 is closed and second exhaustline valve 336 is open to prevent any residual gas from being detectedduring processing a substrate.

The introduction of second exhaust line 334, as described herein,removes residual gas trapped between a second divert valve and a gasdetector, and provides more accurate, more reliable leak detection andanalysis results of the gas supply unit. In addition, methods asdescribed herein that provide a leak check of the gas supply unit beforeprocessing a substrate may prevent potential damage to the substrate bybeing synchronized with an interlock system. Further, a detection may beperformed during a preheating step of the substrate, so the detectiondoes not affect the through-put.

The example embodiments of the disclosure described above do not limitthe scope of the invention, since these embodiments are merely examplesof the embodiments of the invention. Any equivalent embodiments areintended to be within the scope of this invention. Indeed, variousmodifications of the disclosure, in addition to those shown anddescribed herein, such as alternative useful combinations of theelements described, may become apparent to those skilled in the art fromthe description. Such modifications and embodiments are also intended tofall within the scope of the appended claims.

What is claimed is:
 1. A method of using a gas-phase reactor system, themethod comprising the steps of: providing the gas-phase reactor systemcomprising: a reaction chamber; a gas supply unit coupled to thereaction chamber via a gas supply line; a first exhaust system coupledto the reaction chamber via a first exhaust line; a bypass line coupledto the gas supply unit and to the first exhaust system; a gas detectorcoupled to the bypass line via a connecting line; a connecting linevalve coupled to the connecting line; and a second exhaust systemcoupled to the connecting line; exhausting the connecting line; andusing the gas detector, analyzing gas exhausted from the gas-phasereactor system.
 2. The method of claim 1, wherein gas is exhausted fromthe gas supply unit.
 3. The method of claim 1, further comprising a stepof closing a second exhaust line valve between the gas detector and thesecond exhaust system after the step of exhausting the connecting lineand prior to the step of analyzing gas.
 4. The method of claim 1,further comprising a step of exhausting the bypass line during the stepof analyzing.
 5. The method of claim 1, further comprising a step ofloading a substrate within the reaction chamber, wherein the step ofanalyzing is performed after the step of loading and before a step ofunloading the substrate from within the reaction chamber.
 6. The methodof claim 1, further comprising a step of loading a substrate within thereaction chamber, wherein the step of analyzing is performed before thestep of loading.
 7. The method of claim 1, wherein during the step ofanalyzing, gas is exhausted to the second exhaust system.
 8. The methodof claim 7, wherein during the step of analyzing, the gas is notexhausted to the first exhaust system.
 9. The method of claim 1, furthercomprising during the step of analyzing gas, using the gas detector todetermine whether a gas flow rate is above a predetermined level. 10.The method of claim 9, further comprising if the gas flow rate is abovethe predetermined level, stopping flow of gas to the reaction chamber.11. The method of claim 9, further comprising if the gas flow rate isabove the predetermined level, stopping operation of the gas-phasereactor system.
 12. The method of claim 9, further comprising if the gasflow rate is above the predetermined level, engaging an interlocksystem.
 13. The method of claim 1, wherein the step of analyzing isperformed while heating a substrate to a desired process temperature.14. The method of claim 1, wherein the step of analyzing is performedduring a process cycle.
 15. The method of claim 1, wherein the step ofanalyzing is performed after a substrate has been loaded into thereaction chamber and before the substrate is removed from the reactionchamber.
 16. The method of claim 1, wherein during the step ofanalyzing, gas is exhausted to the first exhaust system and the secondexhaust system.